The embodiments described herein relate generally to turbine component s, and more particularly, to methods and systems for forming a micro channel in a turbine component.
In a gas turbine, hot gases flow along an annular hot gas path. Typically, turbine stages are spaced along the hot gas path such that the hot gases flow past buckets and nozzles forming the turbine stages. Conventionally, turbine buckets and nozzles may include an airfoil that extends radially outwardly from a substantially planar platform. A hollow hook portion extends radially inwardly from the planar platform and may include a dovetail or other means to secure the bucket to a turbine wheel. In general, during operation of the gas turbine, the hot gases are generally directed past the airfoil. To protect the airfoil and endwalls from high temperatures, the airfoil may include a cooling circuit that circulates a cooling medium, such as air, within the airfoil. Other turbine component s may be similarly cooled.
The cooling circuit may include a series of micro channels defined within the airfoil or any other hot gas path or combustion component. The micro channels enable the cooling medium flowing through the cooling circuit to be channeled close to the surface of the heated components, such as, but not limited to, airfoils, endwalls, and combustion linings. More particularly, after casting the airfoil, the micro channels are typically machined into surface to be in flow communication with the airfoil cooling circuit. Some processes to form the micro channels include drilling processes, electrical discharge machining processes, and/or abrasive water jet processes. Such, machining processes, however, may add significant costs to manufacturing the airfoil. Moreover, it may be difficult to access portions of the airfoil that are between adjacent airfoils using conventional machining processes. Still further, the conventional airfoil may require a supply plenum and/or a discharge plenum in flow communication with the micro channels to be also machined. Machining a supply plenum and/or a discharge plenum may add significant costs to manufacturing the airfoil and create tolerance issues of coupling the supply plenum and/or the discharge plenum in flow communication with the micro channels.